The diagram illustrates the collection of rainwater and used as drinking water in the town of Australia.
Overall, as the rain is accumulated on the roof top of a building it is collected in the storage through the drain and is treated with chemicals in the water treatment and made utilized for drinking.
Initially as the rain starts to pour the rooftop space above the building collects the water and send it through the drain. The water through the drain will encounter the water filter where the large particles like leaf rocks etc will be filtered out and will be collected in an water storge to go next process.
In the second process the water from the storage is sent to water treatment tank, where the water is treated with chemicals, as the water is treated with chemicals the invisible particles like bacteria, fungus like elements will be removed and will be passed through the pipe for drinking.